The number of illegal immigrants in the United States is nearly double the current and widely reported estimate of 11.3 million, according to a new academic study that uses a more precise method. The research was conducted by professors from two of the nation’s most prestigious universities, the Massachusetts Institute of Technology (MIT) and Yale, and determined that 22.1 million illegal aliens live in the U.S. Even when implementing extremely conservative parameters, the study measures a population of 16.7 million, which is still substantially higher than the figure that is universally accepted by the government and media.

The MIT and Yale researchers say the currently used inaccurate number is based on data from population surveys, which is not very reliable for measuring hidden populations. “In this method, the size of the unauthorized immigrant population residing in the United States is set equal to the estimate of the total foreign-born population minus the legally resident foreign-born population,” researchers write in their report. “The total foreign-born population estimate is derived from surveys that ask respondents whether they were born outside of the United States (and whether they are American citizens), specifically either the American Community Survey or the Current Population Survey.” One of the study’s key researchers, MIT Professor Mohammad Fazel-Zarandi, says surveys aren’t the best method to count illegal immigrants because they probably want to stay undetected. “It’s likely that undocumented immigrants are more difficult to locate and survey than other foreign-born residents and if contacted, they may be inclined to misreport their country of origin, citizenship, and number of household residents, fearing the legal consequences of revealing their status,” Fazel-Zarandi said in a university publication.

That is why the MIT-Yale team used comprehensive government data on border apprehensions, foreigners who overstay visas and deportations as well as immigration and death rates to conduct their broad study. The information used for the research was based on statistics from 1990 to 2016. The team of academics used a sophisticated mathematical model that tracks population inflows and outflows to combine the data and reach the illegal alien population estimate of more than 22 million. It was a very complicated task that involved subcomponents that had to be evaluated for specific level of certainty and incorporated into the mathematical model. The bottom line is that, based on this seemingly reliable method and precise numerical formula, the U.S. has double the illegal immigrants than previously thought. The biggest growth in the illegal immigrant population occurred between 1990 and the early 2000s, the inquiry determined, with the peak in 2007 and 2008. “The results of our analysis are clear: The number of undocumented immigrants for each year is estimated to be substantially larger than has been appreciated at least in widely accepted previous estimates,” the report states.

Regardless of what figure is most accurate, there is no disputing that illegal immigration takes a huge toll on American taxpayers. Those numbers do not lie. A detailed analysis of federal, state and local programs that include education, medical, law enforcement and welfare determined that American taxpayers spend a mind-boggling $134.9 billion annually on illegal aliens. The in-depth probe, conducted by a Washington D.C. nonprofit dedicated to studying immigration issues, reveals that state and local taxpayers get stuck with an overwhelming chunk—$116 billion—of the burden. State and local expenditures for services provided to illegal aliens total $88.9 billion and federal expenditures $45.8 billion, the analysis found. For those who claim illegal immigrants contribute by paying taxes, government figures show that only $19 billion was recouped by Uncle Sam.